Manpage of fft
Section: User Commands (1)
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fft - Fourier transform on image(s)
uv analysis, map making
FFT is a MIRIAD task which performs a fast Fourier transform on
an image. If the input is a cube, then each plane is FFT'ed
individually (i.e. this does not perform a 3D FFT).
Blanked pixels in the input images are treated as if the pixel
If the input image is not a power of two in side, the image is
blank padded up to a power of two.
The output of the FFT would normally be complex valued. You can
save the output in any one of several ways -- as the real or
imaginary part, or as the magnitude (amplitude) and phase.
This gives the input real part image. No default.
This gives the input imaginary part image. The default is a zero image.
This gives the sign of the exponent in the transform. -1 gives a
forward transform, +1 an inverse transform. An inverse transform
applies 1/N scaling. The default is a forward transform.
This gives the origin of the transform. If two values are
given, then they are used as the origin in the x and y axis
respectively. If one value is given, then this is used for the
origin for both the x and y dimensions. The default is the
header value for CRPIX1 and CRPIX2 (if they are in the header) or
N/2+1 (if CRPIX is missing from the header).
The output real part image. The default is not to write this image out.
The output imaginary part image. The default is not to write this
The output magnitude (amplitude) image. The default is not to write
this image out.
The output phase image. The default is not to write this image out.
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Time: 18:35:38 GMT, July 05, 2011